// float 
.f-l {
    float: left;
}

.f-r {
    float: right;
}

.f-n {
    float: none;
}

//清除浮动
.clearfix {
    *zoom: 1;
    zoom: 1;
    &:before,
    &:after {
        content: "";
        display: table;
        font: 0/0 a;
    }
    &:after {
        clear: both;
    }
}